In order to solve the over-charging problem of the EV shell battery, a general solution adopted in the industry is to cut off the main circuit before the cell loses efficacy, so as to prevent the battery from being charged continuously thereby ensure the safety of the battery.
At present, for a square shaped shell battery, a current interrupting device (CID) may be adopted. That is, the positive electrode main circuit includes an air pressure deformable plate and a conductive plate which is integrated with the CID as a whole. The periphery of the conductive plate is connected with an electrode tab of bare cell through welding, the CID portion of the conductive plate is connected with the deformable plate as a whole through welding, and the deformable plate is connected with a top cover through welding so as to conduct a current to a positive terminal.
The conductive plate is fixed on the top cover plate through an insulation piece, at the same time, the conductive plate integrated with the CID as a whole is insulated from the top cover plate. However, it is found that the air leaking problem may exist at the fixing hole during using process.